chore(deps-dev): bump mypy from 0.950 to 0.960 (#1224)

Bumps [mypy](https://github.com/python/mypy) from 0.950 to 0.960.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](python/mypy@v0.950...v0.960)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Simon Thulbourn <sthulb@users.noreply.github.com>

Author: dependabot[bot]

poetry.lock

@@ -53,7 +53,7 @@ flake8-eradicate = "^1.2.1"
 flake8-bugbear = "^22.4.25"
 mkdocs-git-revision-date-plugin = "^0.3.2"
 mike = "^0.6.0"
-mypy = "^0.950"
+mypy = "^0.960"
 mkdocs-material = "^8.2.7"
 mypy-boto3-secretsmanager = "^1.23.8"
 mypy-boto3-ssm = "^1.23.0"